A method and system for analyzing carbon allocation and influencing factors in a tamarisk habitat system

Abstract

The present invention belongs to the technical field of carbon neutralization, and discloses a method and a system for analyzing carbon allocation and influencing factors of a tamarisk habitat system. According to the small habitat system of the "leaf, branch, trunk, root, and soil under the root" element cycle of tamarisk, the method proposes a "stereoscopic dissection type" fine measurement method, aiming at carbon capture, transport, and burial, and focuses on measuring the carbon, nitrogen, phosphorus, potassium, sodium, magnesium, and calcium elements that are closely related to the growth and metabolism of tamarisk. The present invention evaluates the carbon sequestration capacity of each organ of tamarisk and the burial rate of soil organic carbon, and reveals the key processes and carbon storage mechanisms of the carbon sink of tamarisk. It provides a new idea for the future carbon storage process of coastal wetland plants-soil and the ecological restoration of saline-alkali land.

Description

Technical Field

[0001] The present invention belongs to the technical field of carbon neutralization, and particularly relates to a method and system for analyzing carbon allocation and influencing factors of a tamarisk habitat system. Background Technique

[0002] Tamarix chinensis (hereinafter referred to as tamarisk) is a shrub or small tree of the genus Tamarix in the family Tamaricaceae. It is widely distributed in northern coastal wetlands, tidal flats and other areas, and is one of the important species in the "Southern Red and Northern Willow" ecological project in China. It has the characteristics of salt tolerance, drought resistance, waterlogging tolerance, sand burial tolerance and barren tolerance. In coastal saline soil areas, as a typical salt-secreting plant, tamarisk can excrete excess salt through salt glands to regulate salt balance, effectively promoting the improvement and utilization of coastal saline soil. The successful experience of planting tamarisk in Weifang Binhai area to promote the ecological restoration of saline-alkali land shows that this species has the advantage of large-scale cultivation and promotion.

[0003] Large areas of natural tamarisk grow on the Yellow River Delta tidal flats, playing an important role in maintaining the stability of the coastal ecosystem. In the modern Yellow River Delta wetland area, tamarisk has a more advantageous photosynthetic cycle than Suaeda glauca and Phragmites australis with a larger distribution range. Changes in factors such as soil salinity, water, and nutrient salts in the saline-alkali land area of the Yellow River Delta will affect the physiological and ecological processes, photosynthesis efficiency, morphological characteristics, and carbon storage capacity of each organ of tamarisk. In addition, tamarisk forest is an important part of the coastal biological carbon pool, and coastal tamarisk forest is not included in the existing carbon sink trading.

[0004] Current research status and development trends.

[0005] (1) Current research status of the ecological characteristics and carbon storage of tamarisk.

[0006] The soil in the Yellow River Delta is characterized by low nutrient content, high salt content, uneven distribution of salinization, and lack of fresh water resources. Soil salt stress affects plant growth and development, the transport process of nutrients, and other physiological and metabolic activities. Tamarix chinensis, as a salt-secreting halophyte, can grow in a salt-stress environment and is one of the early succession species in the estuary riparian zone, widely distributed in the coastal saline-alkali land and wetland habitats of the Yellow River Delta. The Tamarix chinensis shrub-grass community can increase the water content and storage capacity of the surface soil and has an enrichment effect on soil salt, specifically manifested as the closer to the Tamarix chinensis plant, the higher the soil salt content. With changes in soil salt and other factors, there are local variations in the physiological and ecological processes, photosynthetic efficiency, morphological characteristics, and distribution patterns of Tamarix chinensis in the saline-alkali land area of the Yellow River Delta. Tamarix chinensis begins to germinate and grow in mid-April and starts to shed leaves at the end of October, with a photosynthetic duration of about 140 days a year, which has an obvious advantage over Phragmites australis (about 90 days). There has also been some investigation and research on the distribution of organic carbon in the Tamarix chinensis community, but there is a lack of research on the mechanism that links the growth and metabolic processes of Tamarix chinensis with carbon sequestration. Therefore, the element cycling process between the various organs of Tamarix chinensis and the soil, as well as the carbon storage effect, requires more in-depth research.

[0007] In 2023, the present invention collected the biomass of typical salt marsh vegetation such as Tamarix chinensis, Suaeda glauca, and Phragmites australis in the Yellow River Delta and conducted relevant experimental tests. The measurement results of the organic matter content showed that there were differences and regularities in the total organic carbon (TOC) and δ 13 C of various organs of Tamarix chinensis: The TOC of the annual branches of different tree ages was the highest, the TOC of the main trunk was the lowest, the TOC of the leaves was relatively low, the TOC of the perennial branches was at an average level, and the TOC of the roots was on the low side; the total average value of TOC of various organs of three Tamarix chinensis trees of different tree ages was about 43%, and the difference was not significant. The total average values of TOC of Phragmites australis and Suaeda glauca measured in the same habitat were 33% and 39% respectively. The δ 13 C of the leaves of Tamarix chinensis was the lowest, the δ 13 C of the branches was relatively high, and the δ 13 C of the roots was relatively high; the average value of δ 13 C of three Tamarix chinensis trees of different tree ages showed an obvious pattern of decreasing with the increase of tree age. The average values of δ 13 C of 3-year-old, 6-year-old, and 9-year-old Tamarix chinensis were -23.6‰, -25.5‰, and -27.4‰ respectively. In the soil, at a depth of 0 - 5 cm, the TOC content of Tamarix chinensis was higher than that of Phragmites australis and Suaeda glauca, while the average organic carbon content at a depth of 5 - 25 cm was only 0.11%.

[0008] (2) Key processes and influencing factors of carbon cycling in coastal wetlands.

[0009] Salt marsh wetlands are characterized by the obvious zonal distribution of plants and low species diversity, have very high primary and secondary productivity, a relatively fast carbon accumulation rate, and are collectively referred to as the coastal blue carbon ecosystem together with mangroves and seagrasses.

[0010] The carbon sequestration pathways in salt marsh wetlands include organic carbon sequestered, transformed, and stored through plant photosynthesis, the respiration processes of animals and plants, and microbial decomposition in coastal wetland ecosystems, as well as the capture and burial of carbon in the interaction between wetland vegetation and terrestrial runoff and tides. The key biological processes for the formation of blue carbon in salt marsh wetlands mainly include: (1) carbon sequestration through vegetation photosynthesis, converting CO2 and water into organic matter (such as glucose) and oxygen; (2) photosynthetic carbon allocation and transformation, where synthesized organic matter such as glucose is transported into the cells of leaves and then to stems and roots, and at the same time, a part is transformed into different forms of organic compounds such as starch, cellulose, and protein and stored in plants; (3) rhizosphere deposition, where plant roots release organic matter into the soil through rhizosphere deposition; (4) soil carbon loss, affected by tides and hydrological processes, carbon can migrate, deposit, and store at the soil-water interface. Soil active organic carbon includes dissolved organic carbon (DOC), microbial biomass carbon (MBC), easily oxidized carbon (EOC), and particulate organic carbon (POC), etc. Minor changes in the soil carbon pool can greatly regulate the carbon budget of the ecosystem and become an important factor restricting the carbon sequestration potential of salt marsh wetlands.

[0011] Under the background of strong land-sea interaction and frequent human activities, the soil organic carbon (SOC) in coastal wetlands has strong spatio-temporal heterogeneity. Wetland type and hydrological effects are the key environmental factors affecting the wetland soil carbon cycle. Habitat change has a significant impact on the availability of wetland soil nutrients, physical and chemical properties, and microbial community structure, thereby leading to changes in the distribution of soil carbon components. Hydrological conditions are the key factors affecting the morphology, species distribution, productivity, sedimentation rate, pollutant transport, nutrient cycling, and availability of coastal wetlands. The physical and chemical properties of the soil in wetland ecosystems are also controlled and maintained by factors such as hydrological conditions, water-salt distribution patterns, and the interaction between fresh and salt water, such as periodic tidal effects and the frequency of wet-dry alternation, thus affecting the soil carbon sequestration process.

[0012] Coastal wetlands such as salt marshes have great blue carbon potential, but the key mechanism of its carbon sequestration is still unclear. Current research mostly focuses on the distribution of soil organic carbon components under single environmental factors and their effects on the carbon sequestration function of salt marsh wetlands, rarely considering the systematic effects of multiple processes and their relative contributions, and lacking comprehensive mechanism discussions. Previous studies have hardly touched on the element cycle in the microenvironment of "plant body - soil under the root".

[0013] (3) Analysis of carbon storage in the Yellow River Delta wetland.

[0014] The formation and distribution of wetland vegetation in the Yellow River Delta are significantly affected by the degree of soil salinization and the depth of soil waterlogging caused by the distance from the sea and the altitude. In the estuary area, the salt marsh vegetation types are mainly hygrophytic and halophytic plants, showing an alternating succession of halophytic vegetation from the sea to the land and hygrophytic vegetation from the river channel to both sides, mainly in a progressive succession.

[0015] Many existing researchers have studied the soil organic carbon storage and influencing factors in the Yellow River Delta. By sampling and analyzing the soil organic carbon in the 0-30 cm layer of different landscape types in the Yellow River Delta, it is found that the surface soil organic carbon density of reed wetlands and tidal flats in the Yellow River estuary area ranges from 13.3 to 15.4 Mg C ha −1 . It is pointed out that the tributaries of the Yellow River estuary change frequently, with deposition and erosion alternating, which is not suitable 210 for Pb dating. Using historical geography and sediment geology dating methods, the sediment samples taken in 2007 were studied, and the sedimentation rate and carbon burial rate of reed and Suaeda salsa wetlands were calculated. It is found that the sedimentation rate of salt marsh wetlands in the Yellow River Delta is 3.87–9.68 cm·a –1 , while the carbon burial rate is 586-1784 g·m –2 ·a –1 , much higher than the average value of the carbon sequestration rate of global salt marsh wetlands (168 g·m –2 ·a –1 ), indicating a very high carbon burial capacity of the coastal wetlands in the Yellow River Delta. The accumulation rate of exogenous particulate inorganic carbon (PIC) is relatively high. The accumulation rate of POC is closely related to the plant species in the delta wetlands. The POC accumulation rates of different species from high to low are reed, Suaeda salsa, and cotton. Through field soil sampling, it is pointed out that due to differences in vegetation type, invasion type, and climate zone, the soil organic carbon density of coastal wetlands varies greatly, and the SOC density in the Yellow River Delta is the lowest. There is a lack of research on including Tamarix chinensis wetlands in the carbon storage assessment of salt marshes in the Yellow River Delta and exploring its carbon sequestration mechanism and the distribution pattern of soil organic carbon. Summary of the Invention

[0016] To overcome the problems in related technologies, the disclosed embodiments of the present invention provide a method and system for analyzing carbon allocation and influencing factors in a Tamarix chinensis habitat system.

[0017] The technical solution is as follows: The method for analyzing carbon allocation and influencing factors in a Tamarix chinensis habitat system includes:

[0018] S1, analyzing the carbon storage characteristics of a typical Tamarix chinensis habitat system. Select typical Tamarix chinensis to set up sample plots, and use a three-dimensional anatomical measurement method to collect samples of various organs of Tamarix chinensis and soil profiles; test and analyze the biogeochemical elements of carbon, nitrogen, phosphorus, potassium, sodium, magnesium, and calcium in different components of leaves, branches, trunks, roots, and soil under the roots to obtain the carbon storage amounts of various organs of Tamarix chinensis;

[0019] S2. Conduct a discussion on the carbon cycle mechanism of the typical Tamarix habitat system, analyze the carbon absorption, distribution, and buried matter element cycling processes in the vertical direction of the typical Tamarix habitat system; analyze the sedimentation characteristics of the soil profile, quantify the changes in physical and chemical properties in the soil profile, and calculate the soil carbon burial rate; obtain the effects of the rhizosphere sedimentation effect of Tamarix on the soil, and determine the key influencing factors of organic carbon burial; obtain the relationship between the carbon distribution of each organ of Tamarix and the physical and chemical properties of soil organic carbon and each element, and analyze the response relationship between vegetation biomass, element characteristics, and each environmental factor in the soil.

[0020] S3. Conduct a preliminary assessment of the spatio-temporal distribution pattern and carbon storage of Tamarix forests. Based on phenology and time-series remote sensing images, reconstruct the growth curve of Tamarix vegetation in the Yellow River Estuary, extract the spatio-temporal distribution characteristics of salt marsh wetlands, analyze the spatial distribution characteristics of Tamarix forests, and the environmental factors affecting the distribution of Tamarix forests; based on the carbon storage test results of the typical Tamarix habitat system, evaluate the carbon storage and carbon storage potential of current wetlands Tamarix in the Yellow River Estuary.

[0021] In step S1, a three-dimensional anatomical measurement method is used to collect samples of each organ of Tamarix and the soil profile, including:

[0022] Taking the ground as the reference, construct a local measurement coordinate system with the intersection point of the base stem of Tamarix and the ground as the coordinate origin, the north direction as the x-axis, the south direction as the y-axis, and the vertical direction as the z-axis;

[0023] Above-ground sampling: In the coordinate system, mark the parameters of plant height, crown width, crown diameter, and number of branches. Above-ground samples are divided and collected according to three organs: the main stem, multi-year branches, and leaves, and are collected at multiple levels according to the growth years of the branches; perform three-dimensional spatial positioning and numbering on each sample;

[0024] Underground sampling: Taking the base stem of Tamarix as the center, set two soil profiles in the x-axis and y-axis directions. The control range for collecting soil samples in each profile is 1m×1m underground. Sampling is carried out according to a 10cm×10cm grid. Perform spatial positioning on the roots, and measure the root width, root diameter, rooting depth, main root, lateral root length, diameters before and after branching of each level of roots, the number of internal connections, the number of external connections, and the connection length of the roots until all the shrub roots are dug out. Remove the attached sand, gravel, and sundries on the roots, weigh their fresh weight, and put them into a sealed bag.

[0025] In step S1, test and analyze the biogeochemical elements of carbon, nitrogen, phosphorus, potassium, sodium, magnesium, and calcium in different components of leaves, branches, trunks, roots, and soil under the roots, including:

[0026] Weigh the fresh weights of the leaf, branch, stem, and root organs separately and store them in sealed bags. Put the Tamarix leaves, branches, stems, and roots into an oven at 105°C for 30 minutes for fixation, then dry them at 80°C until constant weight, weigh them, calculate the moisture content of each organ based on the fresh weight and dry weight, estimate the biomass of each organ, and add up the biomass of each organ of the standard plant to obtain the biomass of the whole standard plant.

[0027] Determine the total organic carbon (TOC) and total nitrogen (TN) of the Tamarix leaves, branches, stems, and roots: Use a plant multi-functional grinder to crush and grind the dry weight samples of each component of the dried plants, pass them through a 100-mesh sieve, and use an elemental analyzer to measure.

[0028] Carbon isotope δ 13 C, nitrogen isotope δ 15 N test: Use an isotope mass spectrometer to analyze the extracted organic carbon and nitrogen.

[0029] Plant phosphorus, potassium, sodium, magnesium, and calcium elements: Determined by atomic absorption spectrophotometry combined with inductively coupled plasma mass spectrometry.

[0030] After air-drying the soil samples, remove the coarse debris and stones, grind them, and pass them through a 100-mesh sieve to measure the soil physical and chemical properties, soil organic carbon and its components, and soil major element indicators.

[0031] (1) Determination of soil physical and chemical properties

[0032] Determine the soil bulk density (BD) and soil water content (SWC): Use an aluminum box to hold the soil samples and dry them in an oven at 105°C until constant weight for measurement.

[0033] Determine the soil electrical conductivity (EC), pH value, and soil salinity: Use a pen-type conductivity meter, a portable pH value tester, and a pen-type digital salinity meter to measure them on-site respectively.

[0034] Particle size detection: Take the sample, add pure water, add sodium hexametaphosphate solution, soak, stir, perform ultrasonic vibration, add high-speed centrifugation, measure the particle size through a laser particle size analyzer, and then calculate the particle size parameters.

[0035] (2) Determination of soil organic carbon and its components

[0036] Total carbon (TC), total nitrogen (TN): Use an elemental analyzer to detect the samples of the freeze-dried and 100-mesh sieve-passed soil samples.

[0037] Soil organic carbon (SOC), organic nitrogen (ON): Weigh about 0.5 g of the freeze-dried and 100-mesh sieve-passed samples, remove the inorganic carbon, wash with acid, freeze-dry, and use an elemental analyzer to measure.

[0038] Dissolved organic carbon (DOC): Weigh the freeze-dried and sieved soil samples, add potassium sulfate solution, oscillate on a reciprocating shaker, let it stand and filter the supernatant, and measure it with a total organic carbon analyzer. At the same time, measure the blank sample and the standard sample;

[0039] Microbial biomass carbon (MBC): Use the chloroform fumigation method and measure it with a total organic carbon analyzer;

[0040] Easily oxidizable organic carbon (EOC): Weigh the samples with a carbon content in the range of 15 - 30 mg, add KMnO4, oscillate, centrifuge, take the supernatant and dilute it with deionized water at a ratio of 1:500, and colorimetric at 565 nm;

[0041] Particulate organic carbon (POC): Weigh the sieved soil samples, add sodium hexametaphosphate, oscillate at 25 °C and 90 r / min, then sieve, rinse until the filtrate is colorless and clear, collect the residue, dry it to a constant weight, calculate the proportion in the soil, and combine with the measured soil organic carbon content to calculate the particulate organic carbon content;

[0042] (3) Determination of main elements in soil

[0043] Total phosphorus (TP): Measure by colorimetry using a UV-visible spectrophotometer;

[0044] Soluble ions: Use ion chromatography to determine the content of Cl － 、SO4 2－ in the soil; Use atomic absorption spectrophotometry combined with inductively coupled plasma mass spectrometry to determine the content of K + 、Ca 2+ 、Na + 、Mg 2+ in the soil; Use the standard H2SO4 titration method to determine the content of HCO 3－ ;

[0045] (4) Determination of loss on ignition (LOI)

[0046] Burn the sample in a muffle furnace at 450 °C for 4 - 8 h, measure the mass loss of the sample, which is oxidized or lost or volatilized in the form of gas; Use an elemental analyzer to analyze the sample for organic carbon and construct an equation for the organic matter content and the organic carbon content of the same sample;

[0047] In step S2, analyze the sedimentary characteristics of the soil profile, including:

[0048] According to the finally selected typical locations, combined with the satellite analysis of the restoration of the change process, determine the formation age of the soil body in the research experimental area, and obtain shallow drill samples at the measurement points for stratigraphic analysis.

[0049] In step S2, determine the key influencing factors of organic carbon burial; obtain the carbon distribution of each organ of Tamarix chinensis, the physical and chemical properties of soil organic carbon, and the relationships among various elements, and analyze the response relationships among vegetation biomass, elemental characteristics, and various soil environmental factors, including:

[0050] Calculate the Pearson correlation coefficient using SPSS 25 to analyze the correlations among SOC, TN, salt content, electrical conductivity, soil pH, elements, and clay content, and establish a regression equation. Determine the applicability of the equation by comparing the accuracy of the equation; use one-way ANOVA to test the differences in soil organic carbon content among different sample plots and depths; use CANOCO 5 for multivariate statistical analysis of vegetation carbon storage and soil physical and chemical parameters to explore the response relationships among vegetation biomass, elemental characteristics, and various soil environmental factors.

[0051] Furthermore, in the determination of loss on ignition (LOI), the calculation of the percentage of weight loss on ignition is as follows:

[0052] Percentage of weight loss on ignition = [(dry weight before combustion - weight after combustion) / dry weight before combustion] × 100;

[0053] The equation for the organic matter content and the organic carbon content of the same sample is:

[0054] Inorganic carbon: SIC=TC-SOC ;

[0055] Among them, SIC is the inorganic carbon, TC is the total carbon, SOC is the soil organic carbon.

[0056] In step S3, based on phenology and time-series remote sensing images, reconstruct the growth curve of Tamarix chinensis vegetation in the Yellow River Estuary, including:

[0057] (1) ETM+ and OLI images in the year before and after the target year, and reconstruct an image set for one year according to the time numbering;

[0058] (2) Collect 80 sample points of Tamarix chinensis, Suaeda salsa, Spartina alterniflora, and Phragmites australis respectively, and extract the values of seven spectral indices, namely the normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), normalized difference water index (NDWI), modified normalized difference water index (MNDWI), land surface water index (LSWI), normalized difference turbidity index (NDTI), and green chlorophyll vegetation index (GCVI) of the time series of the sample points;

[0059] (3) Obtain the growth curve through Savitzky-Golay (SG) filtering and smoothing;

[0060] (4) Perform threshold segmentation according to the differences in the start and end times of the growth periods and the spectral index differences shown at maturity of Tamarix chinensis, Suaeda salsa, Spartina alterniflora, and Phragmites australis.

[0061] In step S3, extract the spatio-temporal distribution characteristics of the salt marsh wetland, and analyze the spatial distribution characteristics of the tamarisk forest, including:

[0062] Based on the Landsat vegetation index and water-related spectral indices of the time series, use a small amount of training data sets to train and extract the thresholds of water bodies and vegetation, calculate the vegetation frequency and water body frequency, and classify the intertidal vegetation coverage area and the bare flat based on this.

[0063] Based on the phenology and time series remote sensing images, apply the green chlorophyll vegetation index (GCVI) and the normalized difference turbidity index (NDTI) to the classification of salt marsh vegetation, and reconstruct the growth curve of the tamarisk vegetation in the Yellow River Estuary.

[0064] In step S3, the environmental factors affecting the distribution of the tamarisk forest include:

[0065] Through structural equation modeling, analyze the direct and indirect effects of driving factors such as soil physical and chemical properties, climate, and hydrology on the carbon storage of the tamarisk forest.

[0066] Another object of the present invention is to provide a tamarisk habitat system carbon allocation and influencing factor analysis system, which is realized by the tamarisk habitat system carbon allocation and influencing factor analysis method described above. This system includes:

[0067] The carbon storage characteristics analysis module of the typical tamarisk habitat system is used to select typical tamarisk to set up sample plots, and use the three-dimensional anatomical measurement method to collect samples of each organ of the tamarisk and soil profiles; test and analyze the biogeochemical elements of carbon, nitrogen, phosphorus, potassium, sodium, magnesium, and calcium in different components of leaves, branches, trunks, roots, and soil under the roots to obtain the carbon storage amount of each organ of the tamarisk.

[0068] The carbon cycle mechanism analysis module of the typical tamarisk habitat system is used to analyze the carbon absorption, distribution, and burial material element cycle process in the vertical direction of the typical tamarisk habitat system; analyze the sedimentation characteristics of the soil profile, quantify the changes in physical and chemical properties in the soil profile, and calculate the soil carbon burial rate; obtain the effect of the tamarisk rhizosphere sedimentation on the soil, and determine the key influencing factors of organic carbon burial; obtain the relationship between the carbon distribution of each organ of the tamarisk and the physical and chemical properties and various elements of soil organic carbon, and analyze the response relationship between vegetation biomass, element characteristics, and various environmental factors of the soil.

[0069] The spatio-temporal distribution law and preliminary carbon storage assessment module of the tamarisk forest is used to conduct a preliminary assessment of the spatio-temporal distribution law and carbon storage of the tamarisk forest. Based on the phenology and time series remote sensing images, reconstruct the growth curve of the tamarisk vegetation in the Yellow River Estuary, extract the spatio-temporal distribution characteristics of the salt marsh wetland, analyze the spatial distribution characteristics of the tamarisk forest, and the environmental factors affecting the distribution of the tamarisk forest; based on the carbon storage test results of the typical tamarisk habitat system, evaluate the carbon storage and carbon storage potential of the current wetland tamarisk in the Yellow River Estuary.

[0070] Combining all the above technical solutions, the beneficial effects of the present invention are as follows: Based on the preliminary experimental work, according to the small habitat system of the element cycle of "leaves, branches, trunks, roots, and soil under the roots" of Tamarix, the "stereoscopic anatomical" fine measurement method is proposed. Aiming at carbon capture, transport, and burial, the elements of carbon, nitrogen, phosphorus, potassium, sodium, magnesium, and calcium, which are closely related to the growth and metabolism of Tamarix, are mainly measured. Evaluate the carbon sequestration capacity of each Tamarix organ and the burial rate of soil organic carbon, and reveal the key processes and carbon storage mechanisms of the carbon sink of Tamarix. Provide a new idea for the future carbon storage process of coastal wetland plants-soil and the ecological restoration of saline-alkali land.

[0071] Coastal wetland ecosystems have a huge carbon sequestration capacity, high carbon sequestration efficiency, and a long carbon storage cycle. The soil organic carbon accumulation rate in estuarine wetlands is significantly higher, and its annual average organic carbon sequestration capacity per unit area exceeds twice that of inland wetlands, playing an important role in regulating the global carbon cycle. Under the background of "dual carbon", the existing natural vegetation carbon pools on land cannot be included in the future carbon sink system, and only the newly added carbon sinks through scientific and technological innovation can enter the carbon trading. By quantifying the carbon sink capacity of Tamarix, determining its value in carbon credit trading, promoting the implementation of carbon emission reduction and carbon sink projects based on natural solutions, and incorporating Tamarix into the domestic and international recognized carbon sink accounting system. Furthermore, economic benefits can be achieved through the carbon trading market. Carbon sink certification and trading will also encourage enterprises and organizations to invest in the planting and protection of Tamarix, forming a virtuous cycle, achieving a win-win situation for both ecology and economy, and promoting the development of related industries and technologies.

[0072] At present, the research on coastal blue carbon rarely considers the systematic effects of multiple processes and their relative contributions, and lacks comprehensive mechanism discussions. By studying the carbon storage effect of Tamarix in the vertical direction of "leaves → branches → trunks → roots → soil under the roots", the mechanism of carbon cycling from photosynthesis - plant body - soil can be revealed; through comprehensive determination of the collected soil samples, obtaining the data of soil organic carbon content at different depths, combined with the geochronology method, the age and deposition rate of the sediment layer can be determined, the vertical burial rate of organic carbon can be calculated, the carbon sink capacity of the wetland can be quantified, and the carbon absorption amount of the wetland can be evaluated.

[0073] There is a relative lack of research on the carbon storage assessment of Tamarix wetlands included in the current estuary wetlands of the Yellow River, a typical area with strong land-sea interactions and a relatively high risk of salinization. There is even less in-depth exploration of its carbon sequestration mechanism. The present invention systematically and comprehensively analyzes the mechanisms of element cycling and carbon distribution in the microenvironment of "plant body - soil under roots" of Tamarix. A "three-dimensional dissection" test method for typical plant habitat systems is established. Through the test and analysis of key elements in Tamarix leaves, branches, trunks, roots, and soil under roots, the element cycling process and rules of the Tamarix habitat system are revealed, the carbon distribution in the "photosynthesis - organism - soil under roots" system is explored, and the carbon storage efficiency and environmental value of Tamarix are clarified. In addition, based on phenology and time-series remote sensing images, the growth curves of typical salt marsh vegetation in the Bohai Rim are reconstructed. For the first time, the green chlorophyll vegetation index (GCVI) and the normalized difference turbidity index (NDTI) are applied to the phenological classification of salt marsh vegetation, and the results are better than those of the normalized vegetation index (NDVI) and the enhanced vegetation index (EVI).

[0074] Currently, there is a lack of research on systematically and comprehensively analyzing the key processes of blue carbon in salt marsh wetlands. Previous studies have hardly touched on the mechanistic research of element cycling and carbon distribution in the microenvironment of "plant body - soil under roots" of Tamarix. This solution proposes a "three-dimensional dissection" fine measurement method to evaluate the key processes of carbon distribution, carbon burial, and carbon sink of typical Tamarix from a microscopic perspective; based on phenology and time-series images, the evolutionary trends of Tamarix in the Yellow River Estuary in the past thirty years are studied from a macroscopic perspective; by combining the microscopic and macroscopic aspects, the carbon storage potential of Tamarix forests in the Yellow River Estuary is explored. It provides a new idea for the future plant-soil carbon storage process in coastal wetlands and the ecological restoration of saline-alkali land. Brief Description of the Drawings

[0075] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present disclosure and used together with the specification to explain the principles of the present disclosure;

[0076] Figure 1 It is a flowchart of the method for analyzing carbon distribution and influencing factors in the Tamarix habitat system provided by an embodiment of the present invention;

[0077] Figure 2 It is a schematic diagram of the key processes of carbon exchange in the Tamarix wetland provided by an embodiment of the present invention;

[0078] Figure 3 It is a schematic diagram of the principle of the method for analyzing carbon distribution and influencing factors in the Tamarix habitat system provided by an embodiment of the present invention;

[0079] Figure 4 It is a schematic diagram of the segmentation of soil sampling points under the Tamarix canopy provided by an embodiment of the present invention. Detailed Description of the Invention

[0080] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following detailed description of the specific embodiments of the present invention will be provided in conjunction with the accompanying drawings. Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0081] The innovation of the present invention lies in: based on the classification of saline marsh features in the Yellow River Delta, the present invention collects samples of various organs of Tamarix chinensis and soil profiles through the field "three-dimensional dissection" method, providing fine three-dimensional spatial data for studying the carbon absorption, distribution, burial efficiency, etc. of the Tamarix chinensis habitat system in the vertical direction. On this basis, the present invention explores the impact of the rhizosphere deposition effect of Tamarix chinensis on the soil and the response relationship between plant growth and various soil environmental factors, deepening the material cycle process and mechanism between "plants - soil". The main innovations are reflected in:

[0082] (1) A "three-dimensional dissection" measurement method for the plant habitat system is proposed to study the carbon storage effect of the "leaf → branch → trunk → root → soil under the root" habitat system in the vertical direction, as well as the response between plant growth and various soil environmental factors, and to explore the key processes of carbon sequestration of Tamarix chinensis and the element cycle process and mechanism between plants and soil. The research results are expected to gain new insights into the principle of plant carbon storage;

[0083] (2) Based on phenology and time-series remote sensing image data, GCVI and NDTI are first applied to the classification of saline marsh vegetation, the distribution characteristics of the Tamarix chinensis forest in the Yellow River Estuary are extracted, and combined with the carbon storage test results of the typical Tamarix chinensis habitat system, the microscopic and macroscopic are combined to evaluate the carbon storage and carbon sequestration potential of the current wetland Tamarix chinensis in the Yellow River Estuary;

[0084] According to the results of preliminary test analysis of the biomass of typical saline marsh vegetation such as Tamarix chinensis, Suaeda salsa, and Phragmites australis collected in the Yellow River Delta, the "three-dimensional dissection" measurement method proposed by the present invention is feasible. By analyzing the carbon storage effect of the "leaf, branch, trunk, root, and soil under the root" of Tamarix chinensis in the vertical direction and the response between plant growth and various soil environmental factors, the mechanism of carbon cycling from photosynthesis - plant body - soil can be revealed. The present invention improves and enhances the three-dimensional dissection measurement method.

[0085] The method for analyzing the carbon distribution and influencing factors of the Tamarix chinensis habitat system provided by the embodiments of the present invention further proposes:

[0086] (1)Analysis of the carbon storage characteristics of the typical Tamarix habitat system: In the Tamarix forest stably developed in the Yellow River Estuary area, select typical Tamarix to set up quadrats, and use the "stereoscopic dissection" sampling method to carefully collect samples of each organ of Tamarix and the soil profile. Test and analyze the biogeochemical elements mainly including carbon, nitrogen, phosphorus, potassium, sodium, magnesium, and calcium in different components of leaves, branches, trunks, roots, and the soil under the roots to obtain the carbon storage capacity of each organ of Tamarix;

[0087] (2)Discussion on the carbon cycle mechanism of the typical Tamarix habitat system: Analyze the vertical material element cycle processes such as carbon absorption, distribution, and burial in the typical Tamarix habitat system; analyze the sedimentation characteristics of the soil profile, quantify the changes in physical and chemical properties in the soil profile, and calculate the soil carbon burial rate; obtain the effect of the rhizosphere sedimentation effect of Tamarix on the soil, and determine the key influencing factors of organic carbon burial. Analyze the relationship between the carbon distribution of each organ of Tamarix and the physical and chemical properties of soil organic carbon and various elements, analyze the response relationship between vegetation biomass, element characteristics and various environmental factors of the soil, and discuss the mechanism of the "plant-soil" element cycle;

[0088] (3)Temporal and spatial distribution law and preliminary carbon storage assessment of the Tamarix forest in the Yellow River Estuary: Based on remote sensing images of phenology and time series, reconstruct the growth curve of the Tamarix vegetation in the Yellow River Estuary, extract the temporal and spatial distribution characteristics of the salt marsh wetland, analyze the spatial distribution characteristics of the Tamarix forest, and analyze the environmental factors affecting the distribution of the Tamarix forest. Based on the carbon storage test results of the typical Tamarix habitat system, evaluate the carbon storage capacity and carbon storage potential of the current wetland Tamarix in the Yellow River Estuary.

[0089] The present invention reveals the element cycle process and law of the Tamarix habitat system by establishing a "stereoscopic dissection" test method for the typical plant habitat system, through the test and analysis of key elements of each organ of Tamarix and the soil under the roots, discusses the carbon distribution and control factors in the "photosynthesis-organism-soil under the roots" system, and clarifies the carbon storage efficiency and environmental value of Tamarix.

[0090] The present invention solves the problem of how to test and analyze the organic carbon migration, burial and circulation mechanism of "Tamarix-soil under the roots", evaluate the carbon storage capacity of Tamarix and the soil burial rate, and further evaluate the carbon storage potential of the Tamarix wetland in the Yellow River Estuary.

[0091] Example 1, as Figure 1 shown, the embodiment of the present invention provides a method for analyzing the carbon distribution and influencing factors of the Tamarix habitat system, including:

[0092] S1. Conduct an analysis of the carbon storage characteristics of the typical Tamarix habitat system, select typical Tamarix to set up quadrats, and use the stereoscopic dissection measurement method to collect samples of each organ of Tamarix and the soil profile; test and analyze the biogeochemical elements of carbon, nitrogen, phosphorus, potassium, sodium, magnesium, and calcium in different components of leaves, branches, trunks, roots, and the soil under the roots to obtain the carbon storage capacity of each organ of Tamarix;

[0093] S2. Explore the carbon cycle mechanism of the typical Tamarix habitat system, analyze the carbon absorption, distribution, and buried material element cycling processes in the vertical direction of the typical Tamarix habitat system; analyze the sedimentary characteristics of the soil profile, quantify the changes in physical and chemical properties in the soil profile, and calculate the soil carbon burial rate; obtain the effect of the rhizosphere sedimentation effect of Tamarix on the soil, and determine the key influencing factors of organic carbon burial; obtain the relationship between the carbon distribution of each organ of Tamarix and the physical and chemical properties of soil organic carbon and various elements, and analyze the response relationship between vegetation biomass, element characteristics and various environmental factors in the soil.

[0094] S3. Conduct a preliminary assessment of the spatio-temporal distribution pattern and carbon storage of Tamarix forests. Based on phenology and time-series remote sensing images, reconstruct the growth curve of Tamarix vegetation in the Yellow River Estuary, extract the spatio-temporal distribution characteristics of salt marsh wetlands, analyze the spatial distribution characteristics of Tamarix forests, and the environmental factors affecting the distribution of Tamarix forests; based on the carbon storage test results of the typical Tamarix habitat system, evaluate the carbon storage and carbon sequestration potential of current wetlands Tamarix in the Yellow River Estuary.

[0095] Example 2, as a specific implementation manner of the present invention, a method for analyzing carbon distribution and influencing factors of the Tamarix habitat system is proposed: The carbon storage process of Tamarix is affected by multiple factors such as biology, pedology, hydrology, and climatology. Its carbon sink function is mainly reflected in the vertical carbon fixation, storage and transportation of plants from "leaves, branches, trunks, and roots" and sediment burial, as well as the exchange of soil organic carbon and inorganic carbon with the nearshore water body under the action of tides in the horizontal direction ( Figure 2 Key processes of carbon exchange in Tamarix wetlands). Based on the classification of salt marsh landforms in the Yellow River Delta, the present invention collects samples of each organ of Tamarix and soil profiles through a field "stereoscopic dissection" method, providing fine three-dimensional spatial data for carbon absorption, distribution, burial rate, etc. in the vertical direction of the Tamarix habitat system. On this basis, explore the effect of the rhizosphere sedimentation effect of Tamarix on the soil and the response relationship between plant growth and various environmental factors in the soil, and deepen the material cycling process and mechanism between "plants - soil".

[0096] Example 3, as Figure 3 shown, as a specific implementation manner of the present invention, a method for analyzing carbon distribution and influencing factors of the Tamarix habitat system is proposed: The present invention is based on literature research and data collection. Through "stereoscopic dissection" measurement methods, remote sensing model methods, and indoor physical and chemical experiments, the above-ground vegetation, underground vegetation, and soil carbon pool components of Tamarix forest land and their relationships are quantified, and the dynamic change characteristics and influencing factors of organic carbon are explored through statistical correlation analysis to evaluate the carbon fixation and storage capacity of Tamarix; extract the spectral index values of time series through remote sensing interpretation and combine with the phenological characteristics of different vegetation to analyze the carbon sequestration potential of current wetlands Tamarix in the Yellow River Estuary; further deepen the element cycling mechanism of Tamarix - soil by redundant analysis of the response relationship between vegetation biomass, element characteristics and various environmental factors in the soil.

[0097] Specifically, it includes data collection, field investigation, indoor experimental analysis, remote sensing image processing, and data analysis;

[0098] Step 1, data collection: The present invention takes the current estuary wetland of the Yellow River as the main experimental area. During the analysis process, basic local environmental information is required, and the specific information collected is shown in Table 1;

[0099] Table 1 Data information:

[0100]

[0101] Step 2, field investigation;

[0102] Step 2.1, three-dimensional anatomical measurement method;

[0103] In the current estuary area of the Yellow River, a typical Tamarix habitat system in a Tamarix forest with strong salt stress and stable development is preferably selected for sampling and analysis. Two Tamarix trees with an age of about ten years are selected, and above-ground biomass, below-ground biomass, and soil samples under the roots are collected. The "three-dimensional anatomical" measurement method proposed by the present invention is used to construct a local measurement coordinate system based on the ground. The intersection point of the base stem of the Tamarix and the ground is used as the coordinate origin, the north direction is the x-axis, the south direction is the y-axis, and the vertical direction is the z-axis.

[0104] Above-ground sampling: Parameters such as plant height, crown width, crown diameter, and number of branches are marked in the coordinate system. Above-ground samples are divided and collected according to three organs: the main stem, multi-year branches, and leaves, and are collected at multiple levels according to the growth years of the branches. Spatial three-dimensional positioning and numbering are carried out for each sample to facilitate later three-dimensional drawing.

[0105] Below-ground sampling: With the base stem of the Tamarix as the center (coordinate origin), two soil profiles are set in the x and y directions. The control range for collecting soil samples in each profile is 1m × 1m underground, and sampling is carried out according to a 10cm × 10cm grid ( Figure 4 Schematic diagram of the division of soil sampling points under the Tamarix crown), and a total of 420 soil samples are collected from two trees. For root sampling, spatial positioning of the roots is carried out, and a tape measure, vernier caliper, etc. are used to measure indicators such as root width, root diameter, rooting depth, main root, lateral root length, diameters before and after branching of each level of roots, the number of internal connections (the part between two branch points is the internal connection), the number of external connections (the part between the branch and the meristem is the external connection), and connection length. Until all the shrub roots are dug out, the attached sand, gravel and other debris on the roots are removed with a brush, and their fresh weight is weighed and put into a sealed bag and taken back to the laboratory.

[0106] Step 2.2, collection and processing of Tamarix leaves, branches, trunks, roots and soil samples;

[0107] Weigh the fresh weights of the leaves, branches, trunks, and roots of each organ separately and store them in sealed bags. Put the leaves, branches, trunks, and roots of Tamarix into an oven at 105°C for 30 minutes for fixation, and then dry them at 80°C until constant weight. Weigh them, calculate the moisture content of each organ based on the fresh weight and dry weight of each organ, and then estimate the biomass of each organ. Add the biomass of each organ of the standard plant to obtain the biomass of the whole standard plant;

[0108] Put the soil samples in sealed bags and bring them back to the laboratory to measure the soil moisture content. After air-drying the soil samples, remove the coarse debris and stones, then grind them with a pestle and mortar, and pass them through a 100-mesh sieve to measure soil physical and chemical properties, soil organic carbon and its components, soil soluble ions and other indicators.

[0109] Step 3, indoor experimental analysis;

[0110] Complete through indoor experiments: determination of soil physical and chemical properties, soil organic carbon and its components; measurement of plant carbon content and elements; chronological analysis;

[0111] Soil bulk density (BD), soil water content (SWC): Use aluminum boxes to hold soil samples and dry them at 105°C until constant weight for measurement;

[0112] Soil electrical conductivity (EC), pH value, soil salinity: Use a pen-type conductivity meter (DDS-220; Sinotester), a portable pH tester (PH-280; Sinotester), and a pen-type digital salinity meter (SA287; Sinotester) to measure on-site respectively;

[0113] Particle size detection: Take several grams of the sample and place it in a glass cup, add pure water, add 5 ml of 0.5 mol / L sodium hexametaphosphate solution, soak the sample for 24 hours, stir gently every 8 hours to fully disperse the sample. Pour all the soaked samples into the sample cell, add ultrasonic vibration and high-speed centrifugation to fully disperse the sample again, then measure the particle size grade, the analysis result error is less than 3, the light obscuration is in the range of 10-20, and then calculate the particle size parameters. Consider particles with a particle size less than 8Ф in each sample as clay. Measure through a laser particle size analyzer (Mastersizer3000; Malvern Instruments);

[0114] Total carbon TC, total nitrogen TN: Wrap the samples of freeze-dried soil samples passed through a 100-mesh sieve with tin boats (20-30 μg) and perform on-machine detection;

[0115] Soil organic carbon (SOC), organic nitrogen (ON): Weigh approximately 0.5 g of the sample after freeze-drying and passing through a 100-mesh sieve, and place it in a 10-ml centrifuge tube. Add 2.5 ml of 10% dilute hydrochloric acid twice to remove inorganic carbon. Then rinse it with ultrapure water three to four times until the pH value of the supernatant is neutral as detected by pH test paper. After freeze-drying and weighing the sample, wrap it with a tin cup and use an elemental analyzer (Vario ELIII; Elementar) to determine the SOC and organic nitrogen contents, and simultaneously detect the blank sample and the standard sample.

[0116] Loss on ignition (LOI): Burn the sample in a muffle furnace at 450 °C for 4 - 8 h to determine the mass loss of the sample, such as oxidation or loss or volatilization in the form of gas. The calculation of the percentage of loss on ignition is as follows:

[0117] Percentage of loss on ignition (%LOI) = [(dry weight before combustion - weight after combustion) / dry weight before combustion] × 100;

[0118] A temperature of 450 °C can ensure that only organic carbon is oxidized. Use a small amount of the sample for organic carbon analysis by an elemental analyzer (Vario EL III; Elementar), and construct an equation for the organic matter content (percentage of loss on ignition) and the organic carbon content of the same sample.

[0119] Inorganic carbon (SIC): SIC=TC-SOC;

[0120] Dissolved organic carbon (DOC): Weigh 25.00 g of the freeze-dried and sieved soil sample and place it in a 200-ml plastic bottle. Add 100 ml of 0.5 mol / L potassium sulfate solution, shake it on a reciprocating shaker for 30 min (300 r / min), let it stand for 30 min, filter the supernatant, place the filtrate in a brown sample bottle and store it at 4 °C. It is determined by a total organic carbon analyzer (TOC-V CPH ; Shimadzu), and simultaneously detect the blank sample and the standard sample;

[0121] Microbial biomass carbon (MBC): Use the chloroform fumigation method and determine it by a total organic carbon analyzer (TOC-V CPH ; Shimadzu);

[0122] Easily oxidizable organic carbon (EOC): Weigh the sample with a carbon content in the range of 15 - 30 mg and passing through a 60-mesh sieve into a 50-ml centrifuge tube, add 25 ml of 333 mmol / L KMnO4, shake it at 250 r / min for one hour, centrifuge at 4000 r for 5 min, take the supernatant and dilute it with deionized water at a ratio of 1:500, and perform colorimetry at 565 nm;

[0123] Particulate organic carbon (POC): Weigh 10 g of sieved soil sample, add 30 ml of sodium hexametaphosphate (5 g / L), shake at 25 °C and 90 r / min for 15 hours, then sieve through a 53-μm sieve, rinse until the filtrate is colorless and clear, collect the residue in an aluminum box, dry at 60 °C to constant weight, calculate its proportion in the soil, and calculate the particulate organic carbon content in combination with the measured soil organic carbon content;

[0124] Total phosphorus (TP): Measured by colorimetry using a "UV-Vis spectrophotometer" (Multiskan SkyHigh; Thermo Fisher) (Ru et al., 2018);

[0125] Soluble ions: The soil Cl － 、SO4 2－ content was determined by ion chromatography (IC-2000; Dionex); The contents of soil K + 、Ca 2+ 、Na + 、Mg 2+ were determined by atomic absorption spectrophotometry (AA-6800; Shimadzu) combined with inductively coupled plasma mass spectrometry (NexION1000; PerkinElmer); The HCO 3－ content was determined by standard H2SO4 titration method;

[0126] Total organic carbon (TOC) and total nitrogen (TN) of Tamarix leaves, branches, trunks and roots: The dry weight samples of each component of the dried plants were crushed and ground using a plant multi-functional grinder, sieved through a 100-mesh sieve, wrapped in a tin cup and determined using an elemental analyzer (Vario EL III; Elementar);

[0127] Carbon isotope δ 13 C and nitrogen isotope δ 15 N tests: Using an isotope mass spectrometer (253Plus; Thermo Fisher), the extracted organic carbon and nitrogen were analyzed;

[0128] Plant phosphorus, potassium, sodium, magnesium, calcium elements: The same test method as for soil samples;

[0129] Age analysis: The study area is mainly the Yellow River Delta lobe formed since 1976. Since 1986, the river mouth channel has swung frequently, so the sediment body belongs to event sedimentation and is not suitable for traditional 210 Pb measurement methods. In this study, according to the finally selected typical locations, combined with satellite analysis to restore the change process, the formation age of the soil body in the study experimental area was finally determined. At the same time, shallow drill samples were obtained at the measurement points for stratigraphic analysis.

[0130] Step 4, remote sensing image processing;

[0131] Temporal spectral remote sensing images can be related to the phenological periods of surface vegetation (De Beurs and Henebry, 2005). Vegetation indices are commonly used indicators for analyzing phenological characteristics. Specific phenological periods include the start of the season (SOS), the peak of the growing season, the start of senescence, or the end of the season (EOS), etc.

[0132] Sentinel-2 has a short revisit period (5 days) and high spatial resolution (providing images with spatial resolutions of 10, 20, and 60 meters). Sentinel-2 time series data images from 2020 and 2023 were selected, interpolated, and smoothed by SG filtering. The threshold method was used to extract the SOS and EOS of typical salt marsh vegetation in the Bohai Rim intertidal zone as a reference for the phenological information extracted by Landsat.

[0133] Landsat series images have a long observation period and can extract surface information on long time scales, but have a long revisit period and often have cloud cover in coastal areas. Therefore, the present invention established the growth curves of typical salt marsh vegetation in the Yellow River Estuary wetland in the past thirty years based on phenology and time series remote sensing images: (1) ETM+ and OLI images in the year before and after the target year were used to reconstruct a high-quality image set for one year according to the time numbering; (2) 80 sample points of Tamarix chinensis, Suaeda salsa, Spartina alterniflora, and Phragmites australis were collected respectively. The present invention first applied GCVI and NDTI to the classification of salt marsh vegetation, extracted the distribution characteristics of Tamarix chinensis forests in the Yellow River Estuary, and extracted seven spectral index values of the normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), normalized difference water index (NDWI), modified normalized difference water index (MNDWI), leaf water content index (LSWI), normalized difference turbidity index (NDTI), and green chlorophyll vegetation index (GCVI) of the sample point time series; (3) The growth curves were obtained by smoothing with SG filtering (Savitzky-Golay filtering algorithm); (4) Threshold segmentation was performed according to the differences in the spectral indices shown at the start and end of the growth periods and at maturity of Tamarix chinensis, Suaeda salsa, Spartina alterniflora, and Phragmites australis.

[0134] The bare flats without vegetation cover were extracted by the threshold segmentation method (Wang et al., 2020). Based on the Landsat vegetation index and water-related spectral indices of the time series, thresholds for extracting water bodies and vegetation were trained using a small amount of training data sets, and the vegetation frequency and water body frequency were calculated and used to classify the intertidal vegetation-covered areas and bare flats. This method reduces the influence of tidal dynamics and has a high mapping accuracy.

[0135] Step 5, data analysis;

[0136] Calculate the Pearson correlation coefficient using SPSS 25 to analyze the correlations among SOC, TN, salt content, conductivity, soil pH, alkalization degree, total alkalinity, elements, and clay content, and establish a regression equation. Determine the applicability of the equation by comparing the accuracy of the equation. Use one-way analysis of variance (ANOVA) to test the differences in soil organic carbon content among different plots and depths (a p-value < 0.05 is considered significant). Analyze the direct and indirect effects of soil physical and chemical properties, climate, hydrology, and other driving factors on the carbon storage of Tamarix forests through structural equation modeling (SEM). Use CANOCO 5 for multivariate statistical analysis of vegetation carbon storage and soil physical and chemical parameters to understand the response relationships between vegetation biomass, element characteristics, and various soil environmental factors.

[0137] Example 3, the present invention provides a system for analyzing carbon allocation and influencing factors in a Tamarix habitat system, including:

[0138] A module for analyzing the carbon storage characteristics of a typical Tamarix habitat system, which is used to select typical Tamarix for plot layout, and collect samples of each organ of Tamarix and soil profiles using a three-dimensional anatomical measurement method; test and analyze the biogeochemical elements of carbon, nitrogen, phosphorus, potassium, sodium, magnesium, and calcium in different components of leaves, branches, trunks, roots, and soil under the roots to obtain the carbon storage amounts of each organ of Tamarix; a module for analyzing the carbon cycle mechanism of a typical Tamarix habitat system, which is used to analyze the vertical processes of carbon absorption, distribution, burial, and other material element cycles in a typical Tamarix habitat system; analyze the sedimentation characteristics of the soil profile, quantify the changes in physical and chemical properties in the soil profile, and calculate the soil carbon burial rate; obtain the effect of the rhizosphere sedimentation effect of Tamarix on the soil, and determine the key influencing factors for organic carbon burial; obtain the relationships between the carbon distribution of each organ of Tamarix, the physical and chemical properties of soil organic carbon, and various elements, and analyze the response relationships between vegetation biomass, element characteristics, and various soil environmental factors;

[0139] A module for preliminary assessment of the spatio-temporal distribution law and carbon storage of Tamarix forests, which is used to evaluate the carbon storage and carbon storage potential of Tamarix; based on phenology and time-series remote sensing images, reconstruct the growth curve of Tamarix vegetation in the Yellow River Estuary, extract the spatio-temporal distribution characteristics of salt marsh wetlands, analyze the spatial distribution characteristics of Tamarix forests, and the environmental factors affecting the distribution of Tamarix forests; based on the test results of the biomass and organic carbon of a typical Tamarix habitat system, evaluate the carbon storage and carbon storage potential of Tamarix in the current wetlands of the Yellow River Estuary.

[0140] The present invention proposes a "three-dimensional anatomical" sampling method, selects typical tamarisk in the Yellow River Estuary for fine sampling, tests elements closely related to the growth and metabolism of tamarisk, quantifies the changes in physical and chemical properties and elements in the soil profile, and further analyzes the relationship between the carbon distribution in each organ and the physical and chemical properties of soil organic carbon and various elements. Study the element cycling process and law of the tamarisk habitat system, explore the carbon allocation and control factors in the photosynthesis-organism-subsoil system, and clarify the carbon storage efficiency and ecological environment value of tamarisk. Based on the test and analysis results of the carbon storage in the typical tamarisk habitat system, a preliminary assessment of the carbon storage and carbon storage potential of the current wetland tamarisk in the Yellow River Estuary is carried out. The scientific goals set by the present invention are reasonable and the content is appropriate, and the established scientific goals can be achieved.

[0141] In October and November 2023, the present invention conducted a field survey, collected plant samples from the tamarisk, Suaeda glauca, Phragmites australis, and "Phragmites australis + Imperata cylindrica" vegetation areas and soil samples of 0-30 cm, and carried out particle size tests, organic carbon tests and other test analyses. The preliminary results clearly show that the "three-dimensional anatomical" method can reveal the differences and regularities of carbon storage in different parts.

[0142] The experimental results show that the present invention proposes a "three-dimensional anatomical" measurement method for the plant habitat system, which is used to analyze the carbon storage effect of the "leaf → branch → trunk → root → subsoil" habitat system in the vertical direction, as well as the response between plant growth and various environmental factors of the soil, and obtains the key processes of the carbon sink of tamarisk, the element cycling process and mechanism between plants and soil. New understandings have been obtained in the principle of plant carbon storage.

[0143] The present invention relies on an advanced and perfect experimental platform, equipped with various equipment for sample collection and processing: Sinotester DDS-220 pen-type conductivity meter, Sinotester PH-280 portable PH value tester, Sinotester SA-287 pen-type digital display salinometer, Malvern Instruments Mastersizer3000 laser particle size analyzer, Elementa Vario EL III element analyzer, Shimadzu TOC-VCPH total organic carbon analyzer, Thermo Fisher Multiskan SkyHigh "ultraviolet-visible spectrophotometer", PerkinElmer NexION1000 inductively coupled plasma mass spectrometer, Thermo Fisher 253 Plus isotope mass spectrometer, muffle furnace, etc., which can meet the experimental requirements of the present invention.

[0144] As described above, it is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be covered by the protection scope of the present invention.

Claims

1. A method for analyzing carbon allocation and influencing factors in a tamarisk habitat system, characterized in that, The method includes: S1. Analyze the carbon storage characteristics of the typical Tamarix habitat system. Select typical Tamarix to set up sample plots, and use a three-dimensional anatomical measurement method to collect samples of each organ of Tamarix and soil profiles. Test and analyze the biogeochemical elements of carbon, nitrogen, phosphorus, potassium, sodium, magnesium, and calcium in different components of leaves, branches, trunks, roots, and soil under the roots to obtain the carbon storage amounts of each organ of Tamarix. S2. Explore the carbon cycle mechanism of the typical Tamarix habitat system, and analyze the carbon absorption, distribution, and burial material element cycling processes in the vertical direction of the typical Tamarix habitat system. Analyze the sedimentation characteristics of the soil profile, quantify the changes in physical and chemical properties in the soil profile, and calculate the soil carbon burial rate. Obtain the effect of the rhizosphere sedimentation effect of Tamarix on the soil, and determine the key influencing factors of organic carbon burial. Obtain the relationship between the carbon distribution of each organ of Tamarix and the physical and chemical properties and various elements of soil organic carbon, and analyze the response relationship between vegetation biomass, element characteristics, and various soil environmental factors. S3. Conduct a preliminary assessment of the spatio-temporal distribution pattern and carbon storage of Tamarix forests. Based on phenology and time-series remote sensing images, reconstruct the growth curve of Tamarix vegetation in the Yellow River Estuary, extract the spatio-temporal distribution characteristics of salt marsh wetlands, analyze the spatial distribution characteristics of Tamarix forests, and the environmental factors affecting the distribution of Tamarix forests. Based on the carbon storage test results of the typical Tamarix habitat system, evaluate the carbon storage and carbon storage potential of current wetlands Tamarix in the Yellow River Estuary. In step S2, determine the key influencing factors of organic carbon burial. Obtain the relationship between the carbon distribution of each organ of Tamarix and the physical and chemical properties and various elements of soil organic carbon, and analyze the response relationship between vegetation biomass, element characteristics, and various soil environmental factors, including: Calculate the Pearson correlation coefficient using SPSS 25 to analyze the correlation between SOC, TN, salt content, conductivity, soil pH, elements, and clay content, and establish a regression equation. Determine the applicability of the equation by comparing the accuracy of the equation. Use one-way analysis of variance to test the differences in soil organic carbon content between different sample plots and depths. Use CANOCO 5 for multivariate statistical analysis of vegetation carbon storage and soil physical and chemical parameters to explore the response relationship between vegetation biomass, element characteristics, and various soil environmental factors. In step S3, based on phenology and time-series remote sensing images, reconstruct the growth curve of Tamarix vegetation in the Yellow River Estuary, including: (1) ETM+ and OLI images in the year before and after the target year, and reconstruct an image set of one year according to the time numbering. (2) Collect 80 sample points of Tamarix, Suaeda salsa, Spartina alterniflora, and Phragmites australis respectively, and extract the values of seven spectral indices of the normalized difference vegetation index NDVI, enhanced vegetation index EVI, normalized difference water index NDWI, modified normalized difference water index MNDWI, land surface water index LSWI, normalized difference turbidity index NDTI, and green chlorophyll vegetation index GCVI of the time series of the sample points. (3) Obtain the growth curve through SG filtering and smoothing. (4) Perform threshold segmentation according to the differences in the spectral indices shown by the start and end times of the growth periods and the maturity periods of Tamarix, Suaeda salsa, Spartina alterniflora, and Phragmites australis. In step S3, extract the spatio-temporal distribution characteristics of the salt marsh wetland, and analyze the spatial distribution characteristics of the tamarisk forest, including: Based on the Landsat vegetation index and water-related spectral indices of the time series, use a small amount of training datasets to train and extract the thresholds of water bodies and vegetation, calculate the vegetation frequency and water body frequency, and classify the intertidal vegetation coverage area and the bare flat beach accordingly; Based on the phenology and time series remote sensing images, apply the green chlorophyll vegetation index (GCVI) and the normalized difference turbidity index (NDTI) to the classification of salt marsh vegetation, and reconstruct the growth curve of the tamarisk vegetation in the Yellow River Estuary; In step S3, the environmental factors affecting the distribution of the tamarisk forest, including: Through structural equation modeling, analyze the direct and indirect effects of driving factors such as soil physical and chemical properties, climate, and hydrology on the carbon storage of the tamarisk forest.

2. The method for analyzing the carbon allocation and influencing factors of the tamarisk habitat system according to claim 1, wherein In step S1, use the three-dimensional anatomical measurement method to collect samples of each organ of the tamarisk and soil profiles, including: Taking the ground as the reference, construct a local measurement coordinate system, with the intersection point of the base stem of the tamarisk and the ground as the coordinate origin, the east-west direction as the x-axis, the north-south direction as the y-axis, and the vertical direction as the z-axis; Above-ground sampling: In the coordinate system, mark the parameters of plant height, crown width, crown diameter, and number of branches. The above-ground samples are divided and collected according to three organs: the main trunk, multi-year branches, and leaves, and collected at multiple levels according to the growth years of the branches; spatially three-dimensionally locate and number each sample; Underground sampling: Taking the base stem of the tamarisk as the center, set two soil profiles in the x-axis and y-axis directions. The control range for collecting soil samples for each profile is 1m×1m underground. Sampling is carried out according to a 10cm×10cm grid. Spatially locate the roots, and measure the root width, root diameter, rooting depth, main root, lateral root length, diameters before and after branching of each level of roots, the number of internal connections, the number of external connections, and the connection length indicators of the dug sample plants until all the shrub roots are dug out. Remove the attached sand, gravel, and sundries on the roots, weigh their fresh weight, put them into a sealed bag.

3. The method for analyzing the carbon allocation and influencing factors of the tamarisk habitat system according to claim 1, characterized in that In step S1, test and analyze the biogeochemical elements of carbon, nitrogen, phosphorus, potassium, sodium, magnesium, and calcium in different components of leaves, branches, trunks, roots, and soil under the roots, including: Weigh the fresh weight of the leaf, branch, trunk, and root organs respectively, and store them in a sealed bag; put the tamarisk leaves, branches, trunks, and roots into an oven at 105°C for 30 minutes for deactivation, and dry them at 80°C until constant weight, then weigh them. Calculate the moisture content of each organ through the fresh weight and dry weight, estimate the biomass of each organ, and add up the biomass of each organ of the standard plant to obtain the total biomass of the standard plant; Determine the total organic carbon (TOC) and total nitrogen (TN) of the tamarisk leaves, branches, trunks, and roots: Use a plant multi-functional pulverizer to crush and grind the dry weight samples of each plant component after drying, pass through a 100-mesh sieve, and use an elemental analyzer to measure; Carbon isotope δ 13 C, nitrogen isotope δ 15 N test: Analyze the extracted organic carbon and nitrogen using an isotope mass spectrometer; Plant phosphorus, potassium, sodium, magnesium, and calcium elements: Determined by atomic absorption spectrophotometry combined with inductively coupled plasma mass spectrometry; After air-drying the soil samples, remove the coarse debris and stones, grind them, and pass through a 100-mesh sieve to measure the soil physical and chemical properties, soil organic carbon and its components, and soil main element indicators; (1) Determination of soil physical and chemical properties Determination of soil bulk density (BD) and soil water content (SWC): Soil samples in aluminum boxes are dried to a constant weight in an oven at 105 °C for determination. Determination of soil electrical conductivity (EC), pH value, and soil salinity: Measured on-site using a pen-type conductivity meter, a portable pH tester, and a pen-type digital salinity meter respectively. Particle size detection: Take the sample, add pure water, add sodium hexametaphosphate solution, soak, stir, perform ultrasonic vibration, add high-speed centrifugation, and determine the particle size through a laser particle size analyzer, and then calculate the particle size parameters. (2) Determination of soil organic carbon and its components Total carbon (TC) and total nitrogen (TN): The samples of freeze-dried and 100-mesh sifted soil samples are detected using an elemental analyzer. Soil organic carbon (SOC) and organic nitrogen (ON): Weigh about 0.5 g of the freeze-dried and 100-mesh sifted sample, remove inorganic carbon, wash with acid, freeze-dry, and determine using an elemental analyzer. Dissolved organic carbon (DOC): Weigh the freeze-dried and sifted soil sample, add potassium sulfate solution, oscillate on a reciprocating shaker, let it stand and filter the supernatant, and determine it with a total organic carbon analyzer. At the same time, measure the blank sample and the standard sample. Microbial biomass carbon (MBC): Determined by the chloroform fumigation method using a total organic carbon analyzer. Easily oxidizable organic carbon (EOC): Weigh a sample with a carbon content in the range of 15 - 30 mg, add KMnO4, oscillate, centrifuge, take the supernatant and dilute it with deionized water at a ratio of 1:500, and colorimetric at 565 nm. Particulate organic carbon (POC): Weigh the sifted soil sample, add sodium hexametaphosphate, oscillate at 25 °C and 90 r / min, then sieve, rinse until the filtrate is colorless and clear, collect the residue, dry it to a constant weight, calculate the proportion in the soil, and combine with the measured soil organic carbon content to calculate the particulate organic carbon content. (3) Determination of main elements in soil Total phosphorus (TP): Measured by colorimetry using an ultraviolet-visible spectrophotometer. Soluble ions: The Cl content in soil was determined by ion chromatography; the K, Ca, Na, and Mg contents in soil were determined by atomic absorption spectrophotometry combined with inductively coupled plasma mass spectrometry; the HCO content was determined by standard H2SO4 titration method. － , SO4 2－ content; the K + , Ca 2+ , Na + , Mg 2+ content; the HCO 3－ content was determined. (4) Determination of loss on ignition (LOI) The sample is burned in a muffle furnace at 450 °C for 4 - 8 h to determine the mass loss of the sample, which is oxidized or lost or volatilized in the form of gas; the sample is used for organic carbon analysis using an elemental analyzer to construct an equation for the organic matter content and the organic carbon content of the same sample.

4. The method for analyzing the carbon allocation and influencing factors of the tamarisk habitat system according to claim 1, characterized in that In step S2, analyze the sedimentary characteristics of the soil profile, including: According to the finally selected typical location, combined with the restoration of the change process by satellite analysis, determine the formation age of the soil body in the research experimental area, and obtain shallow drill samples at the measurement points for stratigraphic analysis.

5. The method for analyzing the carbon allocation and influencing factors of the tamarisk habitat system according to claim 3, characterized in that In the determination of loss on ignition (LOI), the calculation of the percentage of ignition loss is as follows: Percentage of ignition loss = [(dry weight before combustion - weight after combustion) / dry weight before combustion] × 100; The equation for the organic matter content and the organic carbon content of the same sample is: Inorganic carbon: SIC = TC - SOC; Where SIC is inorganic carbon, TC is total carbon, and SOC is soil organic carbon.

6. A tamarisk habitat system carbon allocation and influencing factor analysis system, characterized in that, This system is realized by the method for analyzing carbon allocation and influencing factors of the tamarisk habitat system described in any one of claims 1 - 5. This system includes: The carbon storage characteristics analysis module of the typical Tamarix habitat system is used to select typical Tamarix for setting up sample plots, and collect samples of each organ of Tamarix and soil profiles using a three-dimensional anatomical measurement method; test and analyze the biogeochemical elements of carbon, nitrogen, phosphorus, potassium, sodium, magnesium, and calcium in different components of leaves, branches, trunks, roots, and soil under the roots to obtain the carbon storage amount of each organ of Tamarix. The carbon cycle mechanism analysis module of the typical Tamarix habitat system is used to analyze the carbon absorption, distribution, and buried material element cycling processes in the vertical direction of the typical Tamarix habitat system; analyze the sedimentation characteristics of the soil profile, quantify the changes in physical and chemical properties in the soil profile, and calculate the soil carbon burial rate; obtain the effect of the rhizosphere sedimentation effect of Tamarix on the soil, and determine the key influencing factors of organic carbon burial; obtain the relationship between the carbon distribution of each organ of Tamarix and the physical and chemical properties of soil organic carbon and each element, and analyze the response relationship between vegetation biomass, element characteristics, and each environmental factor in the soil. The spatio-temporal distribution law and preliminary carbon storage assessment module of the Tamarix forest is used to conduct a preliminary assessment of the spatio-temporal distribution law and carbon storage of the Tamarix forest. Based on phenology and time-series remote sensing images, reconstruct the growth curve of the Tamarix vegetation in the Yellow River Estuary, extract the spatio-temporal distribution characteristics of the salt marsh wetland, analyze the spatial distribution characteristics of the Tamarix forest, and the environmental factors affecting the distribution of the Tamarix forest; based on the carbon storage test results of the typical Tamarix habitat system, evaluate the carbon storage and carbon storage potential of the current wetland Tamarix in the Yellow River Estuary.

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